I found that using coffee stirrers rather than drinking straws work very
well for my young students (kindergarten, 1st - 3rd graders). I cut pipe
cleaners in approx. 1" lengths, students slide pipe cleaner half way into
stirrer, bend and slide on a second stirrer. My k-1 students easily make
2-D shapes. Third graders built 3-D shapes by sliding a second pipe cleaner
section into a stirrer and adding another stirrer.

Another advantage of the stirrers is that they hold less bubble liquid and
thus, drip much less.